Two-mode therapeutic mattress system

ABSTRACT

A two-mode therapeutic mattress system is provided, including a non-powered air mattress, a pressure dispersion cushion, and a selectively operable air diffusion coverlet in a common modular assembly for improved medical management of skin care. The non-powered air mattress includes longitudinal air cylinders providing a static air support system inflated to predetermined pressure. The longitudinal air cylinders are in pressure communication with elasticized reservoirs, in that the air level in the elasticized reservoirs dynamically reacts to changes in pressure in the longitudinal air cylinders, for example upon receipt of a patient upon the mattress system. The pressure dispersion cushion facilitates pressure relief with a number of lateral and longitudinal cuts resulting in a plurality of separate upright support cells, the size and construction of which may vary over the surface of the pressure dispersion cushion so as to provide selective support characteristics. The air diffusion coverlet contains a plurality of air pockets. The air diffusion coverlet operates in two modes: a “therapy mode” such that compressed air from an air compressor is pumped to the air diffusion coverlet, and an “off” mode in which the air pockets collapse to provide a suitable and relatively smooth bedding component to the therapeutic mattress system. The non-powered air mattress, pressure dispersion cushion, and selectively operable air diffusion coverlet cooperate to provide a single product that addresses localized pressure, maceration, shear stress, and dynamic changes in a patient&#39;s condition during the course of time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No.60/512,882, filed Oct. 21, 2003.

BACKGROUND OF THE INVENTION

This invention concerns a therapeutic mattress system that may beoperated in two modes. More specifically, this invention concerns atwo-mode therapeutic mattress system including a non-powered airmattress, a pressure dispersion cushion, and a selectively operable airdiffusion coverlet in a common modular assembly for improved medicalmanagement of skin care.

Bedridden, non-ambulatory, or immobile patients are at increased risksfor the development of breakdown of the integrity of the skin. Suchbreakdown may lead to the development of lesions, ulcers, sores, and thelike. Such maladies may result in part from physiological causes such asdecreased circulation, impaired nutrition, reduced skin thickness andviability, and other bodily weaknesses. However, external factors mayalso contribute to the development of such maladies. For example,localized pressure to the skin occurs from support of the patient'sweight upon a bedding system. Because different portions of the humanbody have different weights, and have different surface areas fordistribution of that weight upon a bedding system, different pressurecan be brought to bear at various locations along the body. Localizedpoints of relatively great pressure are particularly troublesome in themanagement of skin care and the prevention of skin ulcers. Thedispersion specifically of localized points of greater pressure, andgenerally of the weight of the body, to as broad a surface area aspossible is helpful in avoiding the development and/or progression ofskin ulcers, and also to promote the healing of existing skin ulcers.

Another external cause that may exacerbate the development of skinulcers is maceration, a softening of the skin by soaking or steeping inmoisture. As a person lies in a bed, perspiration from skin in contactwith the bedding surface may tend to accumulate rather than evaporate,inasmuch as air circulation to the location of the accumulation isinhibited or limited by the very occurrence that caused theaccumulation—skin in contact with the bedding surface. By remaining incontact with the skin, the moisture softens the skin and makes it moresusceptible to breakdown, and thereby more susceptible to thedevelopment of skin ulcers. However, management of maceration across aspectrum of patients, even within a single facility such as a hospitalor a nursing home, is not simple. While one particular patient may havea tendency for maceration, perhaps from an individual tendency toperspire more, a second particular individual may suffer from quite dry,frangible skin, perhaps from a tendency to perspire less. It would beuseful for such a facility to have a uniform system, in part for thereduction of costs, that would nevertheless allow for selectiveemployment or avoidance of modalities for the management of maceration,depending upon the particular needs of individual patients.

Still a third external exacerbation of the tendency of the developmentof skin ulcers is shear stress upon the skin. Shear stress occurs, inpart, from the friction of rubbing the surface of the skin. For thebed-bound person, shear most often occurs specifically between theperson's skin and the bed linens upon the mattress. However, the degreeand extent of that shear stress is influenced by the surface features ofthe mattress or padding beneath the bed linens. It is helpful in themanagement of skin care to employ bedding systems with technologiesadapted for the reduction of shear between the skin of a patient and thebedding system.

Healthcare costs are another factor that must be recognized for themanagement of skin care in the avoidance of skin ulcers. Skin ulcers,which potentially may lead to infections, bleeding, and secondarymaladies and complications, increase the cost of care to the patient. Atthe same time, however, increased costs are associated with avoiding thedevelopment of such maladies and with treating existing ulcerations. Forexample, systems to address the exacerbation of localized pressure as acontributor to skin ulcers may not also address maceration as a factor;for a facility to warehouse both systems increases the cost to thefacility for such services. Still further, a system for reducing shearstress to the skin may not be ideal for addressing either localizedpressure or maceration, or both, and thereby increase costs stillfurther. Furthermore, it must be recognized that the skills of thecaregivers called upon to employ such systems may not be uniform suchthat simplicity in using any such system would be desirable as loweringthe likelihood of mistake or misuse.

It may be found also that, as any two patients may have varying needs, aparticular individual patient may have needs that change over time, evenduring the course of a single day. For example, a particular patient mayhave a tendency toward perspiring during the afternoon hours, at thehottest part of the day, but toward dry skin, or even overly dry skin,during the evening and night hours. For such a patient, a system that isnot adjustable to therapeutically address the perspiration during theafternoon hours so as to thereby reduce maceration, yet allow for normalperspiration or even externally-applied moisturizers and emollientsduring the evening, may tend to worsen rather than improve thatparticular patient's condition.

It must also be recognized that patient care is far more expansive thansimply providing for the prevention or improvement of skin sores. Forexample, patients may tend to move about upon the surface of a bed,including involuntary movements during sleep. Many bed systems havelarge metal rails or similar devices to prevent the patient fromaccidentally rolling out of the bed, but such barriers may prove awkwardand obstructive otherwise, and may tend to provide psychologicaldetriment to the patient. Furthermore, such systems interfere with entryupon and egress from the bed when needed.

Higher localized pressures on the heels of a supine patient upon a bedare still another particular aspect of the interplay between the patientsupport surface and the development of pressure sores. The relativelyexcessive pressures focused on the heels are often difficult to reduce,in part simply from the configuration of the human anatomy—a supinepatient upon a relatively flat bedding surface tends to generate higherlocalized pressure upon the heels.

To combat the development of skin ulcers, the medical practice hasemployed the use of various mattress systems, including foam mattressesand air mattresses. However, while addressing particular causes of thedevelopment of skin ulcers, such products have not provided a solutionin a single product that addresses localized pressure, maceration, shearstress, and dynamic changes in a patient's condition during the courseof time.

SUMMARY

In response to the discussed difficulties and problems, a new two-modetherapeutic mattress system has been discovered.

According to the present invention, an integrated mattress system isprovided that includes the combination of non-powered air mattressbladders, foam cushioning providing systematized pressure dispersion,and selectively operable low volume air diffusion to the skin of apatient reclined thereon, along with improved heel comfort and internalbolsters for prompting a patient away from the edges of the bed system.

The present invention includes a mattress system adapted for fast, easysetup by caregivers. It includes a vapor permeable, yet fluidimpermeable, exterior cover comprised of material easily cleaned, whichmay be bacteriostatically treated, may have antistatic construction andmaterials, may be treated with anti-fungal modalities, and may providefor flammability prevention or reduction.

The present invention includes beneath the exterior cover an airdiffusion coverlet. According to the invention, the air diffusioncoverlet is constructed of air permeable material. Such material isformed into inflatable pockets about the surface of the air diffusioncoverlet. Such pockets may be disposed about the entirety of the surfacefor acceptance of a patient thereon, or disposed only in preselectedlocations of the surface. The pockets are inflated by means of anexternal air compressor. The air compressor may be operable in therapymode, such as to provide compressed air to the air diffusion coverlet.Alternatively, the air compressor may be selectively inoperable, suchthat compressed air is not provided to the air diffusion coverlet. Inthe first operation, with compressed air provided by the air compressorto the air diffusion coverlet, compressed air is provided to theinflatable pockets of the air diffusion coverlet. Under pressure, thecompressed air is allowed to slowly escape from the inflatable pocketsthrough small orifices in the pocket material, or through the weave ofthe material, or through the structure of nonwoven substrates; thecompressed air is directed toward the patient upon the bed, therebyresulting in transfer or evaporation of any accumulated moisture as wellas reduction of heat buildup. In the second operation, with the aircompressor selectively turned off, no such air flow is provided to thepatient via the air diffusion coverlet, but nevertheless the airdiffusion coverlet need not be removed from the bedding system, as itprovides a suitable and therapeutic component to the mattress systemeven in its non-powered mode.

The present invention also includes a pressure dispersion cushionbeneath the air diffusion coverlet. The pressure dispersion cushion maybe formed of compressible material, such as polyurethane foam. Thepressure dispersion cushion may include lateral cuts, from side to side,along its surface, of varying or constant depth, so as to create ribs inthe pressure dispersion cushion. Such ribs would provide individuallyresponsive support to the patient reclined upon the mattress system,allowing for reduction of localized pressure upon the skin of thepatient. Additionally, the pressure dispersion cushion may include notonly lateral cuts but also longitudinal cuts, perpendicular to thelateral cuts, upon its surface. Likewise, the longitudinal cuts may beof varying or uniform depth. So configured with lateral and longitudinalcuts, individual cells would be created, the cells being individuallyresponsive to pressure from bearing the weight of a patient reclinedupon the mattress system. About the perimeter of the pressure dispersioncushion, a bolster may also be provided in the present invention. Thebolster, too, is comprised of compressible material, such aspolyurethane foam, but is less compressible, and may be more dense, thanthe material used for the pressure dispersion cushion described here andabove. As such, the perimeter bolster is firmer and would thereby gentlyprompt a patient reclined upon the bed away from the edges of the bed,without awkward obstructions from other devices, such as bed rails orgates, interfering with entry to and egress from the bed surface.

The pressure dispersion cushion described hereinabove may also include aheel relief incline portion. The heel relief incline portion wouldreside in a plane slightly inclined as compared to the general plane ofthe other aspects of the pressure dispersion cushion. So configured, theheel relief incline would redistribute load from the heels of a patientreclined upon the bed to the calves, while providing complete footsupport.

Beneath the pressure dispersion cushion of the present invention lies aplurality of compressed air cylinders. The compressed air cylinders arecomprised of a resilient substrate and lie longitudinally along thelength of the therapeutic mattress system. The longitudinal aircylinders are inflated upon manufacture and sealed for permanentretention of the air held therein, thereby providing a static air systemfor permanent use in a therapeutic setting. So configured, thelongitudinal air cylinders remain compressed during the life of themattress system, and do not deflate during power outages or accidentaldisruption of electrical power to the mattress system. The longitudinalair cylinders are in pressure communication with one or more elasticizedreservoirs disposed beneath the pressure dispersion cushion. Theelasticized reservoirs may be partially enclosed within elastic sleeves,providing for compression of the air disposed within the reservoirs. Inpressure communication with the longitudinal air cylinders, theelasticized reservoirs receive air displaced from the longitudinal aircylinders by the weight of a person upon the mattress system, therebyaccommodating the load upon the bedding system and re-equalizingpressures. Furthermore, the air in the longitudinal air cylinders isinjected to a predetermined pressure that, in cooperation with theelasticized reservoirs, prevent the longitudinal air cylinders frombottoming out upon receipt of the weight of a person upon the bed.

Additional objects and advantages of the invention will be set forth inpart in the following description, or may be obvious from thedescription, or may be learned from practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects described above, as well as other apparent aspects,advantages, and objectives of the present invention are apparent fromthe detailed description below in combination with the drawings, inwhich:

FIG. 1 is a perspective view generally from the foot and right side ofthe mattress system, in partial cutaway, with sectional lines forreference in other figures;

FIG. 2 is a perspective view generally from the foot and right side ofthe mattress system;

FIG. 3 is a partial perspective view of the mattress system generallyfrom the foot and right side, particularly showing the air diffusioncoverlet;

FIG. 4 is a partial perspective view of the mattress according to thepresent invention, generally from the foot of the system, particularlyshowing the air diffusion coverlet folded back to reveal the pressuredispersion cushion;

FIG. 5 is a partial perspective view of the mattress system according tothe present invention, generally from the foot and right side of thesystem, particularly showing the air diffusion coverlet and pressuredispersion cushion removed to reveal the longitudinal air cylinders,elasticized reservoirs, and other components;

FIG. 6 is a partial perspective exploded view, showing portions of thepressure dispersion cushion, longitudinal air cylinders, and elasticizedreservoirs, along with other components;

FIG. 7A is a cross-sectional view, taken along line A-A in FIG. 1,illustrating a first exemplary air diffusion coverlet, pressuredispersion cushion, longitudinal air cylinder, and elasticizedreservoirs;

FIG. 7B is a cross-sectional view, taken along line A-A in FIG. 1,illustrating a second exemplary air diffusion coverlet, pressuredispersion cushion, longitudinal air cylinder, and elasticizedreservoirs;

FIG. 8 is a cross-sectional view, taken along line B-B in FIG. 2,illustrating an exemplary air diffusion coverlet, pressure dispersioncushion, and longitudinal air cylinder;

FIG. 9 is a cross-sectional view, taken along line A-A in FIG. 1,showing in dashed lines a diagrammatic of a patient disposed upon themattress system; and

FIG. 10 is an isolated, enlarged side elevational view of a sloping heelpressure relief section in accordance with the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the presently preferredembodiments of the invention, one or more examples which are illustratedin the drawings. Each example is provided by way of explanation of theinvention, not by way of limitation of the invention. For example,features illustrated or described as part of one embodiment may be usedon another embodiment to yield a still third embodiment. It is intendedthat the present application include such modifications and variationsas come within the scope and spirit of the invention. The same numeralsare used to refer to the same features throughout the drawings and thetext that follows.

As shown in FIG. 1, the therapeutic mattress system generally 20includes an air diffusion coverlet 30 atop a pressure dispersion cushion50, which in turn is atop longitudinal air cylinders 70, configured toprovide the widest array of treatment options available at commerciallyreasonable prices. FIG. 1 is a perspective view, in partial cutaway,showing the relative locations of each of these three componentsubsystems. The therapeutic mattress system 20 generally would be usedwith a hospital-type bed, shown in dash lines in FIG. 1, but may be usedon any suitable platform and its therapeutic advantages may be realizedindependent of the type of specific platform employed.

As shown in FIG. 2, the therapeutic mattress system 20 typically wouldbe enclosed within a vapor permeable exterior fitted cover 22. Also asdepicted in FIG. 2, an air compressor 85 is used to provide compressedair to the air diffusion coverlet by means of an air hose 87.

FIG. 3 depicts the therapeutic mattress system 20 with the exteriorfitted cover 22 folded back to reveal the air diffusion coverlet 30. Asdepicted in FIG. 3, the air diffusion coverlet 30 is in “therapy mode”such that compressed air from the air compressor 85 is being pumped tothe air diffusion coverlet 30, inflating the inflatable pockets 35.

FIG. 4 is a partial perspective view of the therapeutic mattress system20 showing the air diffusion coverlet 30 folded back to reveal thepressure dispersion cushion 50. As will be described in greater detailhereinbelow, the pressure dispersion cushion 50 is comprised ofcompressible foam, such as polyurethane foam. However, varioussubcomponents of the pressure dispersion cushion 50 may be made fromfoams of differing compressabilities, for advantageous reasons.

FIG. 5 is a perspective view of the therapeutic mattress system 20 withthe air diffusion coverlet 30 and the pressure dispersion cushion 50removed, with the longitudinal air cylinders 70 and elasticizedreservoirs 73 revealed. As depicted in FIG. 5, the longitudinal aircylinders 70 are disposed lengthwise along the therapeutic mattresssystem 20. In the exemplary embodiment depicted in FIG. 5, theelasticized reservoirs 73 are disposed toward the foot of thetherapeutic mattress system 20.

FIG. 6 is a partial perspective exploded view showing portions of thepressure dispersion cushion 50, the longitudinal air cylinders 70, theelasticized reservoirs 73, and the air lines 76 that provide pressurecommunication between the elasticized reservoir 73 and the longitudinalair cylinders 70. Also depicted in FIG. 6 is a portion of the pressuredispersion cushion 50.

FIG. 7A is a cross-sectional view illustrating a first exemplary airdiffusion coverlet 30, pressure dispersion cushion 50, longitudinal aircylinders 70, and elasticized reservoirs 73. As depicted in FIG. 7A, theinflatable pockets 35 of the air diffusion coverlet 30 may be lateralrelative to the orientation of the therapeutic mattress 20, or may beindividual pockets as explained in more detail herein below.

FIG. 7B is a cross-sectional view illustrating a second exemplaryembodiment of the therapeutic mattress system 20, in which theinflatable pockets 35 of the air diffusion coverlet 30 are longitudinalalong the length of the therapeutic mattress system 20.

FIG. 8 is a cross-sectional view illustrating an exemplary air diffusioncoverlet 30, pressure dispersion cushion 50, and longitudinal aircylinders 70. FIG. 8 also depicts the perimeter bolsters 58 along thelateral sides of the pressure dispersion cushion 50; the pressuredispersion cushion 50 is represented by crosshatching of a givendirection, whereas the perimeter bolsters 58 are represented bycrosshatching of a different orientation.

FIG. 9 is a cross-sectional view showing in dashed lines a diagrammaticrepresentation of a patient 95 disposed upon the therapeutic mattress20, received upon the inflatable pockets 35 of the air diffusioncoverlet 30. As depicted in FIG. 9, the air diffusion coverlet 30, thepressure dispersion cushion 50, and the longitudinal air cylinders 70conform under the weight of a patient 95 to the shape of the patient 95disposed upon the therapeutic mattress 20.

Finally, FIG. 10 is an enlarged side elevational view of an isolatedportion of the pressure dispersion cushion 50, showing the heel reliefincline 64 for redistributing pressure from the heels of the patient 95to the patient's calves.

In greater detail, it may be understood that the exterior fitted cover22 may comprise various fabrics, such as a stretch fabric of differentmaterials. Such fabric may be provided with other technologicalfeatures, for example treated so as to be easily cleaned. Furthermore,the exterior fitted cover 22 may be treated with bacteriostatic agents,anti-static agents, anti-fungal agents, and flame retardants. Theexterior fitted cover 22 is vapor permeable, so as to allow diffusion ofcompressed air from the inflatable pockets 35 of the air diffusioncoverlet 30 to reach the patient 95 so as to provide evaporation ofaccumulated moisture and dissipation of built-up heat. Cover 22comprises material that, though vapor permeable, is fluid impermeable,or at least largely fluid resistant, such that perspiration and/oraccidental bodily waste upon the therapeutic mattress system 20 will notpenetrate through the cover 22 so as to reach the air diffusion coverlet30. Such fluid impermeability or resistance may be realized by anynumber of known commercial means, including weaving techniques andsurface treatments.

The air diffusion coverlet 30 likewise comprises fabric, either woven ornonwoven, providing for air permeability. Such air permeability may berealized through the relative tightness of the weave of woven fabric,the relative interconnectedness of the fibers of nonwoven fabric, oreven by the mechanical perforation of the fabric to create small holesthere through. The air diffusion coverlet 30 receives compressed airfrom the air compressor 85 via an air hose 87. The air diffusioncoverlet 30 is a “low air loss” system, meaning that compressed airwithin the inflatable pockets 35 escapes the inflatable pockets 35slowly so as to provide gentle, non-disruptive air flow to the skin ofthe patient 95.

The air diffusion coverlet 30 may have inflatable pockets 35 of variousconfigurations. As illustrated in FIGS. 1 and 3, the inflatable pockets35 may be configured to be relatively smaller individual, rectangularpockets, such that individual pockets may be observed not only laterallyacross the therapeutic mattress system 20, but also longitudinally so asto create a grid of such inflatable pockets 35 upon the air diffusioncoverlet 30. Alternatively, and as illustrated in FIG. 7B, theinflatable pockets 35 may be longitudinal members of a longitudinallength approximating that of the therapeutic mattress system 20. Ineither event, the inflatable pockets 35 are in air communication withone another, such that compressed air from the air compressor 85 will betransferred from one inflatable pocket 35 to another, such that, oncethe pressure from the air compressor 85 within the air diffusioncoverlet 30 reaches equilibrium, each inflatable pocket 35 will havesubstantially the same internal positive pressure of air compressedtherein. It is to be understood that the air diffusion coverlet 30includes at least two layers of substrate, with the inflatable pockets35 defined between the two substrates; the inflatable pockets 35 may beformed by selective gluing, heat welding, stitching, or the like betweenthe two layers of substrate to form the inflatable pockets 35.Regardless of the method of construction, provision is made for aircommunication between and amongst the inflatable pockets 35 bypredetermined locations of no gluing, no heat welding, no stitching, orthe like so as to create vapor pathways between the inflatable pockets35.

It is also to be understood that the billow of the inflatable pockets 35shown in the Figures is depicted for illustration purposes only.Different sized inflatable pockets 35 may be practiced, includingparticularly different dimensions of the internal chambers 36 of theinflatable pockets 35, with different amounts of billowing of theindividual inflatable pockets 35.

The air compressor 85 provides compressed air to the air diffusioncoverlet 30 via the air hose 87. The air hose 87 connects with the airdiffusion coverlet 30 by any of a number of conventional means alreadyknown in commerce, all of which are intended to be quick anduncomplicated. As such, the air compressor 85 and the air hose 87 may bebrought to a particular therapeutic mattress system 20 and connectedsimply, with minimal disruption to the patient 95 received upon themattress system 20. The air compressor 85 is selectively operablebetween a “therapy mode” in which it provides compressed air to the airdiffusion coverlet 30, and an off mode in which no such air is provided.When the air compressor 85 is in off mode, the internal chambers 36 ofthe air diffusion coverlet 30 contain no compressed air, and collapse toprovide a suitable and relatively smooth bedding component to thetherapeutic mattress system 20. When the air compressor 85 is in therapymode, the flow rate of air from the compressor 85 to the air diffusioncoverlet 30 via the air hose 87 may be varied, either by valving or byadjusting the speed of operation of the air compressor 85. In such way,the therapeutic effect of the air diffusion coverlet may be regulatedfor individual patient needs. In another embodiment, the air flow fromthe air compressor 85 to the air diffusion coverlet 30 may be cooled orheated, as might be medically advantageous in particular treatmentcases. Still further, the composition of the air flow to the airdiffusion coverlet 30 may be modified, such that air compressor 85provides humidified air to the air diffusion coverlet 30, or providesair impregnated with medicinal agents such as topical antibiotics,emollients, fragrances, decongestants, or antiseptics; such agents maybe introduced into such air flow at the air compressor 85, or along thelength of the air hose 87.

The pressure dispersion cushion 50 may include a variety ofconstructions designed and intended to facilitate pressure relief.Pressure relief, for example, may be provided by a number of lateralcuts 54 formed in such surface, along with a number of longitudinal cuts52 that may also optionally be provided. Such lateral and longitudinalcuts 54, 52 may be practiced in any of the embodiments herewith,although for clarity they are represented only in FIGS. 1 and 4. Thecombination of lateral cuts 54 and longitudinal cuts 52 results in aplurality of separate upright support cells 56, the size andconstruction of which may vary over the surface of the pressuredispersion cushion 50 so as to provide selective supportcharacteristics. Examples of such various arrangements as may bepracticed in combination with the subject invention are discussed incommonly owned U.S. Pat. Nos. 4,862,538; 5,025,519; 5,252,278;5,580,504, the complete disclosures of which are fully incorporatedherein by reference. It should be understood that the appended Figures,for example FIG. 8, depict a thickness of pressure dispersion cushion 50relative to a thickness of longitudinal air cylinders 70 forillustration purposes only. Pressure dispersion cushion 50 may have anyadvantageous thickness relative to the thickness of longitudinal aircylinders 70, for example less than one-half, as may be foundtherapeutically beneficial in individual circumstances.

As depicted, for example, in FIG. 4, the pressure dispersion cushion 50also includes perimeter bolsters 58. The perimeter bolsters 58 arefabricated of compressible material, but are less compressible than thepressure dispersion cushion 50. It is understood in the art that variousnomenclatures may describe support characteristics of given mixtures ofcompressible foam. For example, “IFD” is intended to refer to the knowncharacteristic of so-called indentation force deflection. Indentationforce deflection (IFD) may be defined as the number of pounds ofpressure needed to compress a fifty square inch circular plate into apad of a given percentage deflection thereof. For example, a 25% IFD of30 lbs. would mean that 30 lbs. of pressure is required to push a 50square inch circular plate into a 4″ pad a distance of 1″ (that is, 25%of the original, unloaded thickness). Using a 25% IFD characteristic fordescription purposes, the perimeter bolsters 58 may exhibit a 50-58 lb.IFD, for example 54 pounds, while the pressure dispersion cushion 50 mayexhibit an IFD of less than 44 pounds, for example, 35 pounds. Soconfigured, the mattress system 20 provides a number of features thatmaintains a stable support environment for a patient ingressing toegressing from the mattress system 20. The resulting structure andpractice of the invention results in roll protection, such that apatient might detect, consciously or subconsciously, the greater densityof the perimeter bolsters 58 about the perimeter of the mattress system20 and thereby be prompted away from the edge of the mattress system 20.Additionally, the system provides safer patient entry upon an egressfrom the mattress system 20 by providing a more solid, less compressibleboundary around the outer dimensions of the mattress system 20.

As depicted in the exemplary embodiment shown in FIG. 6, the bottomsurface of pressure dispersion cushion 50 may alternatively be cut toprovide predetermined ridges 51 to act as retainers for the longitudinalair cylinders 70, providing inter-locking between the two subsystems andthereby improving structural integrity.

As depicted in FIG. 10, the therapeutic mattress system 20 may alsoinclude a heel relief incline 64. The heel relief incline 64 is asloping heel pressure relief section for redistributing load fromrelatively less tolerant heel areas of a patient reclined upon mattresssystem 20 to relatively more pressure-tolerant lower legs and calves. Atthe heel relief incline 64, an overall angular slope is introduced to aportion of the pressure dispersion cushion 50, as represented by anangle generally 66. The heel relief incline 64 may practice variousranges of angle 66, such as for example 6 degrees, to achieve improvedpatient heel health in different situations. As represented in FIG. 10,the sloping portion of the heel relief incline 64 is primarily achievedby reduction in the size and/or shape of the respective cells 56. Insuch way, a minimum base thickness of the pressure dispersion cushion 50is maintained, despite the angled surface for the heel relief incline64.

As depicted in FIGS. 1 and 6, among others, beneath the pressuredispersion cushion 50 of the mattress system 20 lie longitudinal aircylinders 70. Together with the elasticized reservoirs 73, thelongitudinal air cylinders represent a static air support systeminflated to predetermined pressure at manufacture, for example 0.10pounds per square inch, to suit original manufacturing specifications.Different numbers and sizes of the longitudinal air cylinders 70 may bepracticed, for example four. Additionally, different numbers and sizesof the elasticized reservoirs 73 may be practiced, for example two. Thelongitudinal air cylinders 70 are in pressure communication with theelasticized reservoirs 73 by the air lines 76 connecting there between.The longitudinal air cylinders 70 are integrally formed from polymericfilm. Moreover, the longitudinal air cylinders 70 are independent of oneanother, reacting independently to patient movement upon the mattresssystem 20. While the exemplary embodiment shown in FIGS. 1 and 6 arelongitudinal cylinders, it will be appreciated that laterally-positionedair cylinders may also be practiced within variations of this invention.

The elasticized reservoirs 73 are resiliently actuated, in that the airlevel in the elasticized reservoir 73 dynamically reacts to changes inpressure in the longitudinal air cylinder 70. For example, upon receiptof a patient upon the mattress system 20, air will be displaced from thelongitudinal air cylinders 70 into one or more of the respectivelyconnected elasticized reservoirs 73 through the air lines 76. However,because of the predetermined pressures and elasticities of thelongitudinal air cylinders 70 and the elasticized reservoirs 73, andbecause the elasticized reservoirs 73 each include an annular elasticsleeve 73, all of the air within a particular longitudinal air cylinder70 will not be displaced. Instead, the pressure level between thelongitudinal air cylinder 70 and its inner connected elasticizedreservoir 73 will reach a pressure equilibrium that provides residualsupport to the patient.

So configured, it will be appreciated that the subcomponent system ofthe longitudinal air cylinders 70, elasticized reservoir 73, and annularelastic sleeve 74 function to redistribute air from the longitudinal aircylinders 70 to the elasticized reservoirs 73 to accommodate load uponthe mattress system 20 re-equalized pressures within the system, andsupport the patient accepted upon the mattress system 20 withoutbottoming out. Opposing longitudinal elements 60, in concert with theridges 51, retain the longitudinal air cylinders 70 in proper position.

Various modifications and variations can be made in the embodiments ofthe present invention without departing from the scope and spirit of theinvention. It is intended that the present invention include suchmodifications as come within the scope of the within disclosure, andtheir equivalents.

1. A therapeutic mattress system, comprising: a plurality of pressurizedair bladders; at least one resiliently activated reservoir, said atleast one reservoir in pressure communication with said bladders, suchthat air is transferable between said bladders and said reservoir; afirst perimeter bolster lateral to said bladders and a second perimeterbolster opposite said first perimeter bolster and lateral to saidbladders; a pressure dispersion cushion, said pressure dispersioncushion covering said bladders and said first and second perimeterbolsters; a cover, said cover residing upon said pressure dispersioncushion opposite said bladders, said cover including plural air pockets,said air pockets being air permeable.
 2. The therapeutic mattress systemof claim 1, wherein said pockets are interoperative one to another suchthat air is transferable between adjacent said pockets.
 3. Thetherapeutic mattress system of claim 2, wherein said pockets areconfigured to inflate upon receipt of pressurized air.
 4. Thetherapeutic mattress system of claim 3, wherein said cover includesmeans to release pressurized air through said cover.
 5. The therapeuticmattress system of claim 3, wherein said pockets are relatively flatwhen uninflated.
 6. The therapeutic mattress system of claim 1, whereinsaid cover is fluid impermeable.
 7. The therapeutic mattress system ofclaim 1, said press dispersion cushion further including means forproviding preselected support characteristics.
 8. The therapeuticmattress system of claim 1, wherein said pressure dispersion cushiondefines a support surface opposite said cylinders, further includinglateral cuts of predetermined depth into said support surface.
 9. Thetherapeutic mattress system of claim 8, wherein said pressure dispersioncushion further includes longitudinal cuts.
 10. The therapeutic mattresssystem of claim 1, wherein said first and second perimeter bolstersdefine a first compressibility, said pressure dispersion cushion definesa second compressibility, said second compressibility greater than saidfirst compressibility.
 11. A therapeutic mattress system, comprising: aplurality of pressurized cylinders; at least one resiliently activatedreservoir, said at least one reservoir interoperative with saidcylinders, such that air is transferable between said cylinders and saidreservoir; a first perimeter bolster lateral to said cylinders and asecond perimeter bolster opposite said first perimeter bolster andlateral to said cylinders; a pressure dispersion cushion, said pressuredispersion cushion topping said cylinders and said first and secondperimeter bolsters; a cover, said cover residing upon said pressuredispersion cushion opposite said cylinders, said cover including pluralair pockets, said pockets air permeable at a predetermined rate.
 12. Thetherapeutic mattress system of claim 11, wherein said pockets areinteroperative one to another such that air is transferable betweenadjacent said pockets.
 13. The therapeutic mattress system of claim 12,wherein said pockets are adapted for receipt of pressurized air, saidpockets inflatable upon said receipt of pressurized air.
 14. Thetherapeutic mattress system of claim 13, wherein said pockets arerelatively flat when uninflated.
 15. The therapeutic mattress system ofclaim 11, wherein said cover is fluid impermeable.
 16. The therapeuticmattress system of claim 11, said press dispersion cushion furtherincluding means for providing preselected support characteristics. 17.The therapeutic mattress system of claim 11, wherein said pressuredispersion cushion defines a support surface opposite said cylinders,further including lateral cuts of predetermined depth into said supportsurface.
 18. The therapeutic mattress system of claim 17, wherein saidpressure dispersion cushion further includes longitudinal cuts normal tosaid lateral cuts.
 19. The therapeutic mattress system of claim 11,wherein said first and second perimeter bolsters define a firstcompressibility, said pressure dispersion cushion defines a secondcompressibility, said second compressibility greater than said firstcompressibility.
 20. A therapeutic mattress system, comprising: aplurality of pressurized air cylinders; at least one resilientlyactivated reservoir, said at least one reservoir in pressurecommunication with said cylinders, such that air is transferable betweensaid cylinders and said reservoir; a first perimeter bolster lateral tosaid cylinders and a second perimeter bolster opposite said firstperimeter bolster and lateral to said cylinders, said first and secondperimeter bolsters defining a first compressibility; a pressuredispersion cushion, said pressure dispersion cushion over said cylindersand said first and second perimeter bolsters, said pressure dispersioncushion defining a second compressibility, said second compressibilitygreater than said first compressibility, said pressure dispersioncushion including a support surface opposite said cylinders, saidsupport surface including plural lateral and longitudinal cuts thereinto provide predetermined selective support characteristics; a cover,said cover residing upon said pressure dispersion cushion opposite saidcylinders, said cover including a first and second substrate layer, saidcover including plural inflatable pockets defined between said first andsecond substrate layers, said inflatable pockets being air permeable;said inflatable pockets configured to inflate upon receipt ofpressurized air, to define a first mode; said inflatable pocketsconfigured to collapse relatively flat absent pressurized air therein,to define a second mode; and wherein said cover is selectively operablein either said first mode or said second mode.
 21. The therapeuticmattress system of claim 20, wherein said inflatable pockets are in aircommunication one with another.
 22. The therapeutic mattress system ofclaim 21, wherein said cover is fluid impermeable.
 23. The therapeuticmattress system of claim 22, wherein said pressure dispersion cushionfurther includes a heel relief portion.